1. Field of the Invention
The present invention relates to a method for coating bioactive material and a structured coated with a bioactive material.
2. Background of the Invention
Patients with renal insufficiency undergo hemodialysis therapy. In recent years, the number of renal insufficiency patients has increased. Most patients using hemodialysis therapy developed renal insufficiency due to glycosuria and hypertension. In that case, the patents are likely to also suffer from serious ateriosclerosis. In order to receive hemodialysis therapy, the flow of blood needs to be uninterrupted in the connection portion between the vein and artery for a long period of time.
In Korean Patent, Registration No. 10-0596218 entitled “ARTERIOVENOUS TUBE COATED WITH MEDICATION FOR HEMODIALYSIS PATENT,” a tube was disclosed. That is, an artificial blood vessel of an expanded polytetrafluoroethylene (e-PTFE) is coated with a medication that suppresses the increase of cells and the generation of inflammation, thereby suppressing the strangulation of blood vessels and the inflammation that may be generated when it is planted in the vein and artery.
The e-PTFE is a thin film having fine pores. The e-PTFE is produced as PTFE is expanded in various directions by being extruded at a high temperature and a high pressure. Since the e-PTFE has a small frictional coefficient, it can delay the adsorption of protein when contacting the blood. That is, since the e-PTFE has an anti-thrombosis quality, it is used as a material for creating an artificial blood vessel.
As shown in FIG. 1, an artificial blood vessel connects an artery and a vein of a hemodialysis patient. In order to provide an internal arteriovenous fistula to a patient, a particular portion of the human body needs to be incised by a hypodermic portion and then the artery and vein are perforated. After that, the perforated artery and vein are connected to both ends of an artificial blood vessel. The connected artificial blood vessel is sutured in the incised portion and serves as a blood path to take hemodialysis, together with capillary connecting the arteries and the veins. During the hemodialysis, the artificial blood vessel is connected with an injector from a hemodialyzer, so that the hemodialyzer is located between the artery and the vein.
It is preferable that a patient uses his blood vessel as an artificial blood vessel. However, since his or her blood vessels may be diseased, it is difficult to use it as it is, so an artificial path is established between the artery and the vein. When the artificial blood vessel as the artificial path has been established, neointimal hyperplasia occurs in the portion of connection between the artery and the artificial blood vessel and between the vein and the artificial blood vessel. In that case, an edema forms at the connection portion or the blood vessels are strangulated, so that the artificial blood vessel cannot function as a path. Therefore, a new artificial blood vessel is needed to reduce the strangulation of blood vessels and the development of inflammation.
If the artificial blood vessel implanted to patients is tightly connected with its surrounding tissues, the patient can easily receive hemodialysis treatment. Otherwise, bleeding may occur at the site of the artificial blood vessel after hemodialysis treatment. Therefore, the implanted artificial blood vessel is required to be fixed to its surrounding tissues as the size of the myofibroblast increases.
On the other hand, although an artificial blood vessel, coated with paclitaxel used as an anticancer drug, can remarkably reduce the strangulation of blood vessels and the occurrence of inflammation, compared with an artificial blood vessel that is not coated with medication, it is still disadvantageous as it cannot suppress the increase of myofibroblast.